1. Field of the Invention
This invention relates to highly conductive, structurally coherent webs of non-woven carbon fibers which are particularly adapted for use in producing improved fuel cell electrodes.
2. Description of the Prior Art
Thin, porous, electrically conductive webs of non-woven carbon fibers useful as substrates in electrodes employed in fuel cells and in other harsh environments where thermal stability and chemical inertness is required are known in the art. Before such webs can be used for such purpose, however, it is necessary that the fibers of the web be bonded together in an integral structurally coherent mass by impregnating the web with a carbonizable resin, e.g., a phenolic resin, and then heating the impregnated web to a carbonizing temperature in order to convert the resin to carbon. Furthermore, in order to further improve the electrical conductivity of the web, it is necessary to coat the impregnated web with pyrolytic carbon. The requirement of a binder and the application of a pyrolytic carbon coating, however, and the processing difficulties attendant the treatment of these webs in this manner, renders their use commercially unattractive.